Self-defrosting refrigerator



E. D. moses $486,347

SELF-DEFROSTING REFRIGERATOR 6 Sheets-Sheet l Dec. 30, 1969 Filed Dec; 27, 1968 n A; W/t W 5 I! m HWIM g 1;; I. 25: g EE a 1M1 "1 W. W [M]!!! in! INVENTOR. EDWARD D. GIDSEG ATTORNEYS Dec. 39, 1969 Filed Dec. 27, 1968 E. D. GIDSEG 3,486,347

SELF-DEFROSTING REFRIGERATOR 6 Sheets-Sheet 2 @Y\\\\\Y/ 3s MUM) I INVENTOR. EDWARD D. GI DSEG BY P ,EM, mfgh m ATTOR NEYS Dec. 3%, W69 E. D. GIDSEG -DEFROSTING REFRIGERATOR SELF Filed Dec. 27, 1968 6 Sheets-Sheet 5 Dec. 30, 1969 E. D. GIDSEG 3,486,347

S ELF-DEFROS T ING REFRIGERATOR Filed Dec. 27, 1968 6 Sheets-Sheet 4 Dec. 39, 1969 Filed Dec. '27, 1968 FIG.

E. D. GIDSEG SELFDEFROSTING REFRIGERATOR 6-Sheets-Sh'eet 5 INVENTOR EDWARD D. GIDSEG ATTORNEYS Dec. 30, 1969 E.D G|D$EG 3,486,347

SELF-DEFROSTING REFRIGERATOR Filed Dec. 27, 1968 6 Sheets-Sheet 6 3,486,347 SELF-DEFROSTTNG REFRIGERATOR Edward D. Gidseg, Kings Point, N.Y. Defiance international Limited, 10816 Merrick Blvd,

Jamaica, N.Y. 11433) Continuation-impart of application Ser. No. 599,039, Dec. 5, 1966. This application Dec. 27, 1968, Ser. No. 787,361

Int. Cl. Fd 21/06 U.S. Cl. 62155 6 Claims ABSTRACT OF THE DISCLOSURE A self-defrosting refrigerator includes a food storage compartment and a refrigerating compartment adjacent and insulatable from the food storage compartment but interconnected by first and second passageways. A refrigeration system is mounted within the refrigerating compartment which includes a compressor, a freezer coil, a defroster coil, a blower for circulating frigid air through the passageways to cool the storage compartment during the refrigeration cycle and means for collecting and exhausting the melted frost from the refrigerating compartment into the ambient environment.

CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation-in-part of copending application, Ser. No. 599,039, filed Dec. 5, 1966 now U.S. Patent No. 3,421,338.

BACKGROUND OF THE INVENTION This invention relates to self-defrosting refrigerators and, more particularly to a novel refrigerator-freezer construction in which the refrigeration system is completely separated from the food storage compartments thereby permitting rapid defrosting of the freezer coils and easy accessibility for servicing mechanical equipment. As used herein, the term refrigerator is used to denote both refrigerators and freezers as well as refrigerator-freezers.

SUMMARY OF THE INVENTION The self-defrosting refrigerator of the present invention comprises a food storage compartment divided by a central wall into a freezer section and a refrigerator section. The central wall includes a first opening to permit circulation of chilled air from the freezer section into the refrigerator section and a second opening to permit return circulation of chilled air from the refrigerator section into the freezer section. A refrigerating compartment is adjacent to the food storage compartment, the respective compartments being separated by a wall having first and second openings therein which define first and second passageways interconnecting the compartments. A refrigeration system mounted entirely within the refrigerating compartment comprises a compressor, a freezer coil, a defroster coil adjacent the freezer coil supplying heat to melt frost from the freezer coil during a defrosting cycle, a blower adjacent the freezer coil circulating frigid air through the passageways between the first and second compartments and through the first and second openings in the central wall of the first compartment during the refrigeration cycle to cool the freezer section and the refrigeration section, and means for collecting and exhausting the melted frost into the ambient environment.

Although the passageways between the two compartments remain open during the defrosting cycle the differential density between the cold air in the food storage compartment and the warmer air in the refrigerating compartment inhibits any heat transfer by natural convecl nited States Patent O ice tion which would otherwise tend to raise the temperature in the food storage compartment. Additionally, the elimination of the freezer coil and the remainder of the refrigeration system from the interior of the storage compartment yields an advantage in that it makes possible a greater usable storage capacity Without altering outside dimensions. The refrigeration system of the invention is more economically manufactured and more efiiciently operated because of the savings in the length of copper tubing needed for the freezer coil and because of the reduction of power and heat losses in the system. Finally, because the refrigerator of the present invention is of modular construction it may be serviced more easily since the entire refrigeration compartment may be um-plugged from the storage compartment for service and a similar refrigeration compartment installed in place of the first in a few minutes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation of the refrigerator of the invention with its doors open;

FIG. 2 is a plan view of a first embodiment of the refrigeration system with the walls of its compartment removed;

FIG. 3 is a cross-section of the refrigeration compartment mounted atop the storage compartment taken through line 33 of FIG. 2;

FIG. 4 is a partial section similar to FIG. 3 but illustrating an alternate embodiment of the defrosting system;

FIG. 5 is a plan view of a second embodiment of the refrigeration system with the walls of its compartment removed; and

FIG. 6 is a cross-section of the refrigeration compartment mounted atop the storage compartment taken through line 66 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring initially to FIG. 1, a first embodiment of the self-defrosting refrigerator-freezer of the invention comprises two major components, namely (a) a food storage compartment 10, and (b) a refrigerating compartment 30, The food storage compartment 10 is a completely insulated and is of conventional construction in that it has a rectangular base 11, a pair of parallel vertical side walls 12 and 13, respectively, a vertical rear wall 14, a ceiling 15 and a pair of doors 16 and 17 mounted on hinges at the front portions of the vertical side walls 12, 13, respectively. The storage compartment 10 is divided into two sections, a freezer section 18 and refrigerator section 19, by a central wall 20 which extends vertically from the base 11 to the ceiling 15 in a plane parallel to that of the sidewall 12, 13. The central wall 20 divides the food storage compartment 10 approximately in half but the exact proportions are a matter of design only. The central wall 20 has a first opening 21 near the portion at which it joins the ceiling 15, which opening 21 allows circulation of chilled air from the freezer section 18 to the refrigerator section 19. A second opening 21a in the central wall 20 allows the return circulation of chilled air from the refrigerator section 19 to the freezer section 18. As shown in FIG. 3, the ceiling 15 of the storage compartment 10 has a pair of openings 22 and 23, located in the freezer section 18 adjacent its forward and rear marginal edges, respectively. A cold air circulating duct 24 is mounted on the rear wall 14 of the freezer section 18 extending vertically downwardly from opening 23 and terminating at the lower portion of the rear wall 14 in an outlet orifice 25. An electrically heated mullion strip 26 is mounted on the forward marginal edge of the freezer section 18, the purpose of the strip 26 being to prevent ice from forming on the marginal edges and to ensure an airtight seal between the central wall 20 and the doors 16, 17. Also provided in the storage compartment is a temperature regulator 27 of conventional design which is mounted on the central wall in the refrigerator section 19.

As shown best by FIG. 3, the refrigerating compartment 30 is also completely insulated, having a rectangular base 31 of dimensions identical to those of the ceiling 15 of the storage compartment 10, vertical sidewalls 32, 33, a vertical rear wall 34, and a removable top 35. A vertical front wall 36 of the refrigerating compartment 30 has a portion which defines a louvered exhaust grill 37. A vertical bulkhead 38 which extends from the base 31 to the top in a plane parallel to that of the sidewalls 32, 33 and which is supported by the rear wall 34 divides the refrigerating compartment 30 into a first section 39 and a second section 40. The louvered exhaust grill 37 vents the second section 40 only. The base 31 of the refrigerating compartment 30 is provided with two openings 41, 42 which coincide with openings 22, 23 of the storage compartment 10 together defining passageways which allow circulation of air between the first section 39 of the refrigerating compartment 30 and the storage compartment 10.

A conventional electrically powered compressor 43 is mounted in the second section 40 of the refrigerating compartment and a freezer coil 44 is mounted in the first section 39 of the refrigerating compartment 30 as shown best in FIG. 3. Refrigerant supply and return conduits 45, 46 extend from the compressor 43 through bulkhead 38 to the freezer coil 44. An electrically operated defroster coil 47 is located directly beneath the freezer coil 44 and a melted frost collecting pan 48 is mounted directly beneath the defroster coil 47 as shown in FIG. 3. The melted frost collecting pan 48 has a drain opening in its bottom (not shown) to which is connected a drain conduit 49 shown in FIG. 2. The drain conduit 49 extends through the bulkhead 38 into section 40 of the refrigerating compartment 30 and discharges the melted frost into an evaporator pan 50 which is mounted in section 40. Directly beneath the evaporator pan 50 is an evaporator heating coil 51 (which may be either electrical or hot gas type) which vaporizes the melted frost in the evaporator pan 50. A circulating fan 52 directs a stream of air over the evaporating pan 50 to discharge the vaporized melted frost outwardly through the exhaust grill 37. Mounted in section 39 adjacent freezer coil 44 is a suitably supported blower 53 which circulates cold air throughout the storage compartments 10 during the refrigeration cycle and which circulates hot air throughout section 39 of the refrigerating compartment 30 during the defrosting cycle.

A solenoid 54, mounted on base 31 in section 39, acts through link 55, bell crank 56 and links 57, 58 to translate closure members 59, 60 which are slidably mounted in tracks 61 and 62, respectively, on the base 31 of the refrigerating compartment 30 directly over openings 41, 42. The solenoid 54 is shown in its unactuated mode in FIG. 2; when the solenoid 54 is actuated by timer means 90 at the start of the defrosting cycle it causes the closure members 59, 60 to slide into a closed position thereby completing isolating the refrigerating compartment 30 from the storage compartment 10. An alternate embodiment of this system is shown in FIG. 4, in which a rotary solenoid 154 is employed and closure members 159, 160 are pivotally mounted on base 31. In this alternate embodiment, the closure members 159, 160 are opened and closed by the rotary solenoid 154 acting through links 157 and 158, respectively. However, the significant distinction between the embodiment of FIGS. 2 and 3 and the embodiment of FIG, 4 is that the freezer coil 44, heater coil 47 and circulating fan 53 are mounted above a platform 161 which is positioned in section 39 of refrigerating compartment 30 as shown in FIG. 4. The advantage of this construction is that the space between platform 161 and base 31 defines a passageway 162 which allows for greater circulation of air throughout section 39 during the defrosting cycle thereby further decreasing the cycle duration. When the refrigeration cycle is in progress, closure members 159, 160 are pivoted into a vertical position as shown by the broken lines in FIG. 4 and thus prevent any diversion of air into passageway 162.

As noted above, the self-defrosting refrigerator of the invention has two distinct operating cycles, namely a refrigeration cycle and a defrosting cycle.

During the refrigeration cycle, the solenoid 54 or 154 is unactuated; the refrigerating compartment 30 and storage compartment 10 are interconnected through openings 22, 41 and 23, 42. The compressor 43 circulates refrigerant through freezer coil 44 via condiuts 45, 46. Blower 53 causes a stream of air to pass across the freezer coil 44, downwardly through openings 42, 23 and duct 24, out of orifice 25, upwardly throughout the freezer section 18 and finally upwardly through openings 22, 41 into the refrigerating compartment 30. A portion of this air flow passes through opening 21 in central wall 20 to cool the refrigerator section 19 of storage compartment 10 and is recirculated through opening 21a into the freezer section prior to being returned to the refrigerating compartment 30 for rechilling. Although not shown, a thermostat is positioned at the intake openings to monitor the temperature of the circulating air and to control the rate of defrosting.

Upon initiation of the defrosting cycle by the automatic timer 90, compressor 43 is shut off, defroster coil 47 is actuated and solenoid 54 or 154 is energized, closing closure members 59, 60 or 159, 160 thereby completely sealing the storage compartment 10 from the refrigerating compartment 30. Blower 53 continues to operate now circulating (i.e., by pushing or pulling) hot air over the freezer coil 44 to melt the frost condensed thereon. The liquified frost collects in pan 48- and is drawn off through conduit 49 and into the evaporator pan 50. The evaporator heating coil 51 evaporates the melted frost and the circulating fan 52 circulates an airstream over the evaporator pan 50 causing the evaporated melted frost to be discharged trough the louvered grill 37 into the ambient environment. After a short period, the automatic timer causes the defroster coil 47 to deactivate and the compressor 43 to resume circulation of refrigerant through the freezer coil 44. Blower 53 continues to circulate air throughout section 39 of the refrigeration compartment 30 causing the heat generated during the defrosting cycle to be dissipated rapidly. Shortly afterwards, the solenoid 54 or 154 is deactivated, the closure members 59, 60 or 159, reopen and the refrigeration cycle resumes. Normally, the defrosting cycle may be carried out in less than 5 minutes.

Because of its modular construction the refrigerating compartment 30 may be removed for service as a unit and another similar compartment installed until repairs are completed. Removal of the refrigerating compartment is accomplished by disconnecting from a socket 70 mounted in the refrigerating compartment 30 service lines 71 which lead to the regulator 27 and the heated mullion strip 26 and then sliding the entire refrigerating compartment 30 forwardly and away from the top of the storage compartment 10.

Referring now to FIGS. 5 and 6, a second embodiment of the present refrigerating includes a food storage compartment which is substantially identical to the compartment 10 of the first embodiment and therefore the reference characters used to describe the food storage compartment 10 shall also be employed in the dscription of the second embodiment.

The refrigerating compartment 20a of the second embodiment, shown best by FIG. 6, is completely insulated, having a rectangular base 31a of dimensions identical to those of the ceiling 15 of the storage compartment 10,

vertical sidewalls 32a, 33a, a vertical rear wall 34a, and a removable top 35a. A vertical front wall 36a of the refrigerating compartment a has a portion which defines a louvered exhaust grill 37a and a vertical front wall 36b which is spaced inwardly from wall 36a completes the insulation of the refrigeration compartment 30a. A vertical bulkhead 38:: which extends from the base 31a to the top a in a plane parallel to that of the sidewalls 32a, 33a and which is supported by the rear wall 34a divides the refrigerating compartment 30a into a first section 39a and a second section 40a. The louvered exhaust grill 37a is operative across its entire length but vents the second section 40a only. The base 31a of the refrigerating compartment 30a is provided with two openings 41a, 42a which coincide with openings 22, 23 of the storage 10 compartment together defining passageways which allow circulation of air between the first section 39a of the refrigerating compartment 300 and the storage compartment 10.

A conventional electrically powered compressor 43a is mounted in the second section 40a of the refrigerating compartment 30a and a freezer coil 44a is mounted in the first section 39a of the refrigerating compartment 30a as shown best in FIG. 6. Refrigerant supply and return conduits 45a, 46a extend from the compressor 43a through bulkhead 38a to the freezer coil 44a. An electrically operated defroster coil 47a is located directly beneath the freezer coil 44a and a melted frost collecting pan 48a is mounted directly beneath the defroster coil 47a. The melted frost collecting pan 48a has a drain opening in its bottom (not shown) to which is connected a drain conduit 49:: shown in FIG. 5. The drain conduit 49a extends through the bulkhead 38!: into section 40a of the refrigerating compartment 300 and discharges the melted frost into an evaporator pan 50a which is mounted in section 400. Directly beneatth the evaporator pan 50a is an evaporator heating coil 51a (which may be either electrical or hot gas type) which vaporizes the melted frost in the evaporator pan 50a. A circulating fan 52a directs a stream of air over the evaporating pan 50a to discharge the vaporized melted frost outwardly through the exhaust grill 37a. Mounted in section 39a adjacent freezer coil 44a is a suitably supported blower 53a which circulates cold air through the passageways between the storage compartment 10 and the refrigerating compartment 30a and through the first and second openings 21, 21a, in the central wall 20 of the storage compartment 10 during the refrigeration cycle.

As noted above, the self-defrosting refrigerator of the invention has two distinct operating cycles, namely a refrigeration cycle and a defrosting cycle.

During the refrigeration cycle, the compressor 43a circulates refrigerant through freezer coil 44a via conduits 45a, 46a. Blower 53a causes a stream of air to pass across the freezer coil 44a, downwardly through openings 42a, 23 and duct 24, out of orifice 25, upwardly throughout the freezer section 18 and finally upwardly through opening 22, 41a to return into section 39a of the refrigerating compartment 30a. A portion of this air flow passes through opening 21 in central wall 20 to cool the refrigerator section 19 of storage compartment 10 and is recirculated through opening 2111 into the freezer section prior to being returned to the refrigerating compartment 30a for rechilling. Although not shown, a thermostat is positioned in a junction box 70a at the intake opening 22, 41a to monitor the temperature of the circulating air and to control the operation of the compressor 43a.

Upon initiation of the defrosting cycle by an automatic timer 90a also mounted in junction box 70a, compressor 43a is shut off, defroster coil 47, is actuated and blower 53a is deactivated to prevent circulation of hot air into the storage compartment 10. The liquified frost collects in pan 48a and is drawn off through conduit 49a and into the evaporator pan 50a. After a short period, the automatic timer a causes the defroster coil 47a to deactivate and the compressor 43a to resume circulation of refrigerant through the freezer coil 44a. The evaporator heating coil 51a evaporates the melted frost and the circulating fan 52 circulates an airstream over the evaporator pan 50a causing the evaporated melted frost to be discharged through the louvered grill 37a into the ambient environment. Blower 53a again begins to circulate air throughout section 390 of the refrigeration compartment 30a and storage compartment 10 as the refrigeration cycle resumes.

Because of its modulator construction the refrigerating compartment 30a may be removed for service as a unit and another similar compartment installed until repairs are completed. Removal of the refrigerating compartment is accomplished by disconnecting from a first socket in the junction box 70a which is mounted outside section 39a of the refrigerating compartment 30a on vertical wall 36b service line 71a which leads to the source of electrical power, thereafter disconnecting from a second socket in the junction box 70a service line 71b which leads to the heated mullion strip 26 and other electrical equipment and then sliding the entire refrigerating compartment 30a forwardly and away from the top of the storage compartment 10.

Although the refrigerators shown in the drawings both illustrate a refrigerating unit positioned above the food compartment, the self-defrosting refrigerators of the invention may be constructed with the refrigerator unit positioned below or even adjacent to the food compartment, depending upon which embodiment is employed and the spatial arrangement desired.

I claim:

1. A self-defrosting refrigerator comprising:

(a) a first compartment for the storage of perishable foodstuffs including a central wall dividing the first compartment into a freezer section and a refrigerator section, the central wall having a first opening to permit the circulation of chilled air from the freezer section to the refrigerator section and a second opening to permit the return circulation of chilled air from the refrigerator section to the freezer section;

(b) a second compartment adjacent to the first compartrnent;

(c) a wall separating the first compartment from the second compartment having first and second openings therein which openings define first and second unobstructed passageways interconnecting the freezer section of the first compartment with the second compartment; and

(d) a refrigeration system mounted entirely within the second compartment comprising:

(i) a compressor;

(ii) a freezer coil;

(iii) a defroster coil adjacent the freezer coil supplying heat to melt frost from the freezer coil during a defrosting cycle;

(iv) a blower adjacent the freezer coil cooling the freezer section and the refrigerator section during the refrigeration cycle by circulating frigid air through the passageways between the freezer section of the first compartment and the second compartment, a portion of the frigid air being further circulated from the freezer section to the refrigerator section through the first opening in the central wall of the first compartment and being returned to the freezer section through the second opening in the central wall; and

(v) means for collecting and exhausting the melted frost from the second compartment into the ambient environment.

2. A self-defrosting refrigerator according to claim 1 wherein the first and second compartments are of modular construction and separable from one another.

3. A self-defrosting refrigerator according to claim 1 (b) a heated evaporator pan vaporizing the melted further including a cold air supply duct extending from frost; the first passageway vertically downwardly along a rear (c) a conduit carrying the melted frost from the colwall of the freezer section of the first compartment and lecting pan to the evaporating pan; and terminating at the lower portion of the rear Wall. (d) a circulating fan mounted adjacent the evaporat- 4. A self-defrosting refrigerator according to claim 1 5 ing pan exhausting the vaporized melted frost into further including a heated mullion strip mounted on a the ambient environment. forward marginal edge of the central wall preventing the accumulation of frost on the forward marginal edge. References Cited 5. A self-defrosting refrigeration system according to 10 UNITED STATES PATENTS claim 1 further including an automatic timer actuating the defroster coil and exhaust means and deactivating the blower at the start of the defrosting cycle.

6. A self-defrosting refrigeration system according to claim 1 wherein the means for exhausting the melted frost 15 comprises:

(a) a melted frost collecting pan mounted beneath the freezer coil; 291

2,731,804 1/1956 Grubbs 62Z75 2,812,642 11/1957 Jacobs 62-419 KR MEYER PERLIN, Primary Examiner 

